An Atlas of Reproductive Anatomy and Physiology for Breeding Barn Managers


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An Atlas of Reproductive Anatomy and Physiology for Breeding Barn Managers

To the reviewer:

Structure and Function of the Female Reproductive System Wayne L. Singleton and Brad A. Belstra Department of Animal Sciences Purdue University

Pole Breeding

Why is a knowledge of the sow’s reproductive system important?

Top reproductive performance requires a combination of successes

Preparation for this presentation Each pan contains one uterine horn

Intact Gilt Reproductive Tract (Non pregnant)

Female Reproductive Tract

Endocrine Glands and Hormones

PPT Slide


Pig ovary just prior to ovulation

Gilt reproductive tract Day 2 post estrus


Towards the end of the normal cycle, the corpora lutea become non functional terminating production of progesterone and become corpora albicans(white bodies). These “white bodies” are the remains of CL’s from the previous cycle.

Hormones and events just before and after estrus (heat) A single follicle and CL are shown

Major hormones of reproduction Which hormone(s) would you expect to find in the blood of this gilt?

Pituitary Gland Located at the base at the base of the brain It is often called the master gland

These are corpora lutea which have been excised from an ovary

Ovarian Structures Normal cycling, nonpregnant gilt


These are 8-celled zygotes about 48 hours after fertilization. They were flushed from the oviduct.

This is another view of the ovarian end of the tract.

Normal Ovary(left) Abnormal Ovary(right)

Describe what you see below

Cervix (Shown with catheter inserted)

Insemination Catheter Placement Note: Cervical Folds

One of the most critical periods of embryonic development is between days 13 and 18 after conception. This when the attachment of the embryos called blastocysts occurs. Pregnant females should not be moved, mixed with new pen mates or in any way stressed at this time.

Development of Porcine Conceptuses from Day 10 to 12

Elongated Day 15 Porcine Conceptus

Prior to attachment to the uterine wall, the embryos can migrate from one uterine horn to another. They extend their membranes along the horn to achieve nearly equal spacing.

PPT Slide

Real-time Ultrasound 28 days post mating

Pregnant Uterine Horn (Trimmed of supporting ligaments)

28 Day Embryo

PPT Slide

This “litter” of 12 embryos was removed from a sow on day 28 post-mating

This litter of 25 embryos was removed from 1 sow on day 28 post-mating.

Embryonic death

Embryonic death and degeneration

Using Crown Rump Length to Determine Fetal Age

During gestation piglets orient themselves at random. About 1/2 are born head first and 1/2 are born tail first. Sometimes piglets will be born 1 or 2 from one horn and then 1 or 2 from the other or sometimes one horn is emptied and then the other. Again it is random. See the Purdue Porkpage for more information on farrowing. (we will put a link here)

This is a reproductive tract from a gilt. It is missing a vagina and cervix.

This is another abnormal reproductive tract from a gilt. What is missing?

Which gilt and which reproductive tract is abnormal? What is this condition called?

Have you observed this abnormality in new born gilts? What is missing?

What is abnormal about this animal?

Attainment of Puberty


Factors influencing the age at puberty

Induced or Programmed Farrowing Using Lutalyse or Estrumate

Physiology and anatomy from farrowing through rebreeding

Assuming a normal farrowing process with no difficulties, the uterus should gradually return to its nonpregnant size within 10 or 12 days.

Why don’t all sows return to heat within 4 to 7 days after they are weaned?

Female Facts

Can you identify the structures and their function?

Author: Wayne Singleton